An update from the Microsoft Engineers:
It looks like we ran into an issue, where the Flow is deleted , but the logic app which runs behind the Flow did not, which is why it is not there for ‘Get Flow’ but List Flow under admin pulls it. It’s a rare occurrence, however, we are working towards this issue and fix the actions.
Can` you confirm from the user whether they want this Flow or not. We can either perform cleanup and remove it, or restore it back for this user. Upon your response, we will proceed with the cleanup, and post that you won’t see this issue.
So I guess there could be a difference in where the two actions look. Microsoft will fix this for us in this specific tenant 👍